I had a look on the source file, the file utils/icon/liquidwar6-icon-32x32.png is really the first ressource file loaded, so not being able to load it probably means something is wrong with the paths.

However this is strange since a serious path wreckage should cause problems even before, more precisely, finding the Guile script (which is the case if you got this message) should be a proof that globally, the directory structure is OK and there's no obvious problem such as non-existing directory and/or flat zip extract.

Can you check that liquidwar6-icon-32x32.png is indeed somewhere on your hard drive, and if yes, where? How about liquidwar6.exe?

There are several errors when I try to launch the game (Windows 7 64-bit):
1. gl-utils-data.c:70
unable to load image utils/icon/liquidwar6-icon-32x32.png
2. mod-gl-setup.c:377
unable to load consts
3. lw6-funcs.c:1623
no graphical backend found, game can only run in server mode

Then nothing happens, but process is still alive in background so I kill it manually.